Re: [PATCH v2] merge-options.txt: correct wording of --no-commit option

On Tue, Feb 19, 2019 at 11:32 AM Junio C Hamano [off-list ref] wrote:

Elijah Newren [off-list ref] writes:

quoted

+With --no-commit perform the merge and stop just before creating
+a merge commit, to give the user a chance to inspect and further
+tweak the merge result before committing.
++
+Note that fast-forward updates do not need to create a merge
+commit and therefore there is no way to stop those merges with
+--no-commit.  Thus, if you want to ensure your branch is not
+changed or updated by the merge command, use --no-ff with
+--no-commit.

While the above is an improvement (so I'll queue it on 'pu' not to
lose sight of it), I find the use of "do not need to" above somewhat
misleading.  It solicits a reaction "ok, we know it does not need
to, but it could prepare to create one to allow us to further muck
with it, no?".

IOW, a fast-forward by definition does not create a merge by itself,
so there is nowhere to stop during a creation of a merge.  So at
least:

        s/do not need to/do not/

Yes, I agree that's a good change.  I'll wait a few days for other
feedback and resend with that and any other changes.

It also may be a good idea to consider detecting this case and be a
bit more helpful, perhaps with end-user experience looking like...

  $ git checkout master^0
  $ git merge --no-commit next
  Updating 0d0ac3826a..ee538a81fe
  Fast-forward
    ...diffstat follows here...
  hint: merge completed without creating a commit.
  hint: if you wanted to prepare for a manually tweaked merge,
  hint: do "git reset --keep ORIG_HEAD" followed by
  hint: "git merge --no-ff --no-commit next".

or even

  $ git checkout master^0
  $ git merge --no-commit next
  warning: defaulting to --no-ff, given a --no-commit request
  Automatic merge went well; stopped before committing as requested
  hint: if you'd rather have a fast-forward without creating a commit,
  hint: do "git reset --keep next" now.

Good points.  I thought of this last one before sending, though
without pre- and post- warnings/hints; without such text it definitely
seemed too magical and possibly leading to unexpected surprises in a
different direction, so I dismissed it without further thought.  But
the warnings/hints help.

I do not have a strong preference among three (the third option
being not doing anything), but if pressed, I'd say that the last one
might be the most user-friendly, even though it feels a bit too
magical and trying to be smarter than its own good.

I also lack a strong preference.  Maybe mark it #leftoverbits for
someone that does?

In any case, the hint for the "recovery" procedure needs to be
carefully written.

Yes.